/* 
 * [New BSD License (BSD 3-Clause License)]
 * Copyright (c) 2012, Max Bechtold
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     - Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     - Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     - Neither the name of the Rel2Xml Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package maxbe.rel2xml.generator.docs.constraints;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import maxbe.rel2xml.generator.docs.DataType;

/**
 * Generates unique numbers starting from 0 and up to the number communicated
 * using the mark method
 * 
 * @author Max Bechtold
 * 
 */
public class RandomNumbers implements ValueConstructor {

	private int minValue;
	private int maxValue;

	private Random rand;
	private static long seed = 323345673;

	private static final List<DataType> types;

	static {
		types = new ArrayList<DataType>();
		types.add(DataType.INTEGER);
	}

	public RandomNumbers(int maxValue) {
		this(0, maxValue);
	}

	public RandomNumbers(int minValue, int maxValue) {
		if (minValue > maxValue) {
			maxValue = minValue;
		}

		this.minValue = minValue;
		this.maxValue = maxValue;
		rand = new Random(seed++);
	}

	@Override
	public boolean lengthVaries() {
		return false;
	}

	@Override
	public int getLength() {
		return -1;
	}

	@Override
	public int getSubLength() {
		return -1;
	}

	@Override
	public boolean needsAnnounce() {
		return false;
	}

	@Override
	public void announce(int number) {
		// No preparation needed
	}

	@Override
	public void mark(int number) {
		// Ignore as RandomNumbers are always global
	}

	@Override
	public String next() {
		return String.valueOf(rand.nextInt(maxValue - minValue + 1) + minValue);
	}

	@Override
	public List<String> next(int number) {
		List<String> result = new ArrayList<String>();

		for (int i = 0; i < number; i++) {
			result.add(String.valueOf(rand.nextInt(maxValue - minValue + 1)
					+ minValue));
		}

		return result;
	}

	@Override
	public String toString() {
		return String.format("random number [%d, %d]", minValue, maxValue);
	}

	@Override
	public List<DataType> getSupportedDataTypes() {
		return types;
	}
}
